1. Field of the Invention
The invention relates to a method for determining a partial-load condition of a system comprising several components, a computer program product, and the use of such an overall system partial-load condition.
2. Description of the Related Art
Conventional systems, i.e., production and manufacturing systems, are at present usually operated at full load, or are completely switched off. In the event of the system being only partially utilized, incurred, for example, due to the circumstances of a particular order, it would be advantageous, not least with regard to energy consumption of the system, to operate the system in a partial-load operational mode.
In addition to the energy advantage referred to, other circumstances, i.e., maintenance intervals and service life of individual components, favor the operation of a system in a partial-load condition, instead of operating the system for a specific time under full load and thereafter having the system in a state of rest.
If it is intended that a complete system is to be operated in a specific partial-load condition then the individual components of this system must naturally be operated in an individual partial-load condition. The term “components” is to be understood to mean, for example, processing devices or robots of a manufacturing line, and also facilities such as conveyor belts and motors, which are frequently provided with an at least minimal electronic control and a more or less significant communications interface for the exchange of process and operational data.
With the operation of individual components of the system in a partial-load condition, it is to be borne in mind that, on the one hand, certain components do not allow for every partial-load condition at will, and that, moreover, possible or permissible partial-load conditions of individual components do not have the same effect on the system. For example, a motor can be operated at 25% of a full capacity provided for, while the machine downstream thereof may only be capable of operation at 50%.
Another problem lies in the fact that the operation of all the components of the system in a specific partial-load condition, such as 50% of the full capacity provided for, has different effects on different components. For example, a partial-load condition of 50% on a first component may have a different effect on its throughput than on a second component. The relationship between partial-load conditions of a component and operating parameters such as the throughput as referred to heretofore, is at present not defined either for individual components or for the system as a whole. Even if a definition were to be available for individual components, a system planner would still be confronted by the problem of realizing an implementation of at least one partial-load condition in a complete system which, due to the differing forms of behavior of individual components, represents an extremely complex problem.